3442 results about "Nanofiltration" patented technology

A composite membrane and method for making the same, comprising a porous support and a polyamide surface. The subject membrane provides improved flux and/or rejection rates. The subject membrane is further capable of operating at lower operating pressures. The subject method includes reacting a polyfunctional amine with a polyfunctional acyl halide to form a polyamide. The method includes the step of contacting a complexing agent with the polyfunctional acyl halide prior substantial reaction between the polyfunctional acyl halide and a polyfunctional amine. The subject process is easily adapted to commercial scale manufacturing processes and is particularly suited for making nanofiltration and reverse osmosis composite membranes.

A desalination process is disclosed which combining two or more substantially different water treatment processes in a unique manner to desalinate saline water, especially sea water, to produce a high yield of high quality fresh water, including potable water, at an energy consumption equivalent to or less than much less efficient prior art desalination processes. In this process a nanofiltration step is synergistically combined with at least one of sea water reverse osmosis, multistage flash distillation. multieffect distillation of vapor compression distillation to provide an integrated desalination system by which sea water can be efficiently and economically converted to high quality potable water in yields which are at least 70%-80% greater than the yields available from the prior art processes. Typically a process of this invention using the nanofiltration initial step will produce, with respect to sea water feed properties, calcium, magnesium, sulfate and bicarbonate ion content reductions of 63%-94%, pH decreases of about 0.4-0.5 units and total dissolved solids content reductions of 35%-50%.

A cross flow filtration apparatus for nanofiltration or reverse osmosis has pressure vessels with a plurality of filter cartridges in each vessel. A feed port is provided at an intermediate position on the side of the vessel, and two permeate flows or branches exit opposite ends of the vessel, and the first branch has a characteristically high “upstream” flux and quality, while the second is of lesser flux and/or quality. The system provides a high degree of moduarity, enhancing flux or yield at a reduced driving pressure or overall pressure drop. Centered or off-center port, and a stop or valve in the permeate stream may apportion flows between the two outlets. Staged systems may employ a first stage bypass to achieve a target quality with increased yield. A flow divider or adaptor permits the cartridges to fit and seal in the vessel and an installation tool or sleeve may facilitate installation or replacement of cartridges having a directional perimeter seal. A tool permits modules to be bi-directional installed in the pressure vessel. Other embodiments involve adapting a conventional vessel designed for end-to-end feed flow utilizing a restrictor, obstruction or valve inside the filter cartridge to bifurcate or otherwise split or apportion the permeate. RO elements may be modified to movably position an obstruction or valve along a string of the elements and vary the take-off to two or more permeate outlets, or to provide pressure relief valves that present different pressure conditions for different elements of a string. A pressure vessel may have an intermediate inlet, with symmetric or asymmetric branching of permeate flow to opposed ends of the vessel, enhancing permeate flux, permeate quality and/or energy efficiency.

A mobile station and methods are disclosed for diagnosing and modeling site specific effluent treatment facility requirements to arrive at a treatment regimen and/or proposed commercial plant model idealized for the particular water/site requirements. The station includes a mobile platform having power intake, effluent intake and fluid outflow facilities and first and second suites of selectably actuatable effluent pre-treatment apparatus. An effluent polishing treatment array is housed at the station and includes at least one of nanofiltration, reverse osmosis and ion-exchange stages. A suite of selectively actuatable post-treatment apparatus is housed at the station. Controls are connected at the station for process control, monitoring and data accumulation. A plurality of improved water treatment technologies is also disclosed. The modeling methods include steps for analyzing raw effluent to be treated, providing a field of raw effluent condition entry values and a field of treated effluent condition goals entry values, and utilizing said fields to determine an initial treatment model including a selection of, and use parameters for, treatment technologies from the plurality of down-scaled treatment technologies at the facility, the model dynamically and continuously modifiable during treatment modeling.

Sodium chloride and purified water are recovered by treating salt water that contains sodium chloride with an integrated reverse osmosis and electrodialysis system, which includes an efficiency-enhancing feature that is one or more of the following: the use of univalent anion and univalent cation selective membranes in the electrodialysis unit; the addition of a nanofiltration unit to process the diluate from the electrodialysis unit; or operation of the electrodialysis unit at an elevated pressure. Magnesium and bromine can optionally be produced when the salt water contains these materials.

Water treatment systems and methods. Embodiments provide water treatment systems which comprise first oxidation, particulate filtration, and membrane filtration subsystems in that order. Systems also comprise recirculation paths and sensors for these subsystems. A controller determines whether to recirculate water to a previous subsystem in the order. Systems can comprise downstream second oxidation, high pressure membrane, ion exchange, activated carbon subsystems and/or ultraviolet contactors. Systems with high pressure membranes can comprise a pump before the high pressure membranes, a booster pump of the high pressure membrane subsystem, and a damping tank. In such systems the controller maintains a pressure in the damping tank. High pressure membrane subsystems can further comprise nanofiltration membranes and RO membranes. Systems can comprise bypass paths for some/all of the subsystems. For such systems, the controller further determines, whether to bypass these subsystems.

A mobile station and methods are disclosed for diagnosing and modeling site specific effluent treatment facility requirements to arrive at a treatment regimen and/or proposed commercial plant model idealized for the particular water/site requirements. The station includes a mobile platform having power intake, effluent intake and fluid outflow facilities and first and second suites of selectably actuatable effluent pre-treatment apparatus. An effluent polishing treatment array is housed at the station and includes at least one of nanofiltration, reverse osmosis and ion-exchange stages. A suite of selectively actuatable post-treatment apparatus are housed at the station. Controls are connected at the station for process control, monitoring and data accumulation. A plurality of improved water treatment technologies are also disclosed.

The invention discloses a desulfurization waste water zero discharging process. The process comprises a chemical dosing softening process and a microfiltration membrane treatment process; after incoming water is subjected to two-stage softening, nanofiltration and reverse osmosis separation are performed; sodium sulfate decahydrate with the purity of more than 99% is separated out by utilizing freezing crystallization; a reverse osmosis concentrated water regeneration sodium ion exchange device is utilized; sodium chloride with the purity of more than 98% is separated out by utilizing evaporative crystallization; solids are comprehensively utilized, and no liquid is discharged outside. The invention further provides a desulfurization waste water zero discharging system. According to the desulfurization waste water zero discharging process and the system, water in desulfurization waste water can be separated to be reutilized as domestic and industrial usable water, and other impurities in the desulfurization waste water are separated in solid form, so that pollutants harmful to the natural environment do not generate, and the problem that the desulfurization waste water pollutes the environment can be completely solved.

The present invention pertains to an apparatus and method for treating a solution of high osmotic strength, especially seawater and solutions of greater than 20 bar osmotic pressure, by passing the solution through a vessel containing spiral wound reverse osmosis or nanofiltration elements. The vessel contains at least three elements in series and at least two of these elements have standard specific fluxed that differ by at least 50%. The invention allows a more even flux distribution within a filtration system to be obtained, and it may advantageously be combined with variations en element construction and feed spacers.

A process for manufacturing xylose by extracting hemicellulose from a cellulosic material, such as by a cold caustic extraction method, concentrating the extract, such as by nanofiltration, into a hemicaustic stream containing hemicellulose with greater than about 85 wt % xylan content, and subsequently hydrolysing the xylan from the hemicaustic stream to xylose. The high concentration of xylan within the concentrated hemicaustic stream enables hydrolyzation of the xylan to food-grade xylose and, optionally, hydrogenation of the xylose to xylitol without the need of a chromatographic separation step as previously required.

An integrated treatment system using electrodialysis and pressure-driven membranes for deionizing and decontaminating liquids to a near-pure quality for use or reuse in industrial or municipal operations. The integrated system includes steps of pre-filtering contaminated feed liquids blending the filtered liquids in preparation for treating the mixed liquids in parallel or sequential treatment steps utilizing nanofiltration or reverse osmosis, proceeded by or followed by an integrated electrodialysis treatment. A control means selectively directs mixed liquids to each of the treatment units for treatment in parallel or in series depending on the conductivity and residual contaminants in the mixed liquids. In comparison with nanofiltration or reverse osmosis only systems, or electrodialysis only systems, the integrated system provides improved efficiencies for treatment, requires less energy to operate, and reduces maintenance and capital costs.

The nanofiltration process is suitable for Mg-Li separation and Li enriching of Li containing bittern or Li containing solution from salt lake to prepare lithium carbonate or lithium chloride with the Li enriching bittern. Nanofiltration membrane is used in separating and enriching lithium from lithium containing bittern, which contains Mg, Ca and other cations and sulfate radical and other anions and has Li ion concentration of 0.1-11.5 g/L and Mg/Li ion weight ratio 1-200, to obtain lithium enriched bittern suitable for preparing lithium carbonate or lithium chloride. The said process is effective, and can obtain lithium enriched bittern with Mg/Li ion weight ratio 0.6-5 and Li ion content of 0.6-20 g/L.

A membrane is provided including a coating layer having cellulose nanofibers produced from oxidized cellulose microfibers and an electrospun substrate upon which the coating layer is applied. The nanofibers of the electrospun substrate have a diameter greater than that of the cellulose nanofibers. The membrane also has non-woven support upon which the electrospun substrate is disposed. Microfibers of the non-woven support have a diameter greater than that of the nanofibers of the electrospun substrate. Application of electrospun membrane is in microfiltration area, while the cellulose nanofiber membrane serves in ultra-filtration, nanofiltration, and reverse osmosis after chemical modification.

A desalination plant for treating a sea water or brackish water feed is provided. The desalination plant includes a first treatment section to effectively remove scaling species, the first treatment section including nanofiltration section, the nanofiltration section including at least two stages and at least two passes; and a reverse osmosis section that operates at high recovery to produce a purified permeate stream and a selectively NaCl salt-enriched reject stream as a saline output.

The invention relates to a hyperfiltration membrane or nanofiltration membrane with a multi-layered composite structure and a preparation method thereof. The hyperfiltration membrane or nanofiltration membrane is a polymer electrostatic spinning nanofiber membrane layer characterized in strong chemical resistance prepared through an electrostatic spinning method, a hydrophilic polymer ultra-thin separation layer obtained through interfacial polymerization, and a functional group surface modification functional layer formed through the grafting reaction of reactant gases on the surfaces of hydrophilic polymers, or a long-chain polymer surface modification functional layer formed through the grafting reaction of the reaction gases on the surfaces of the hydrophilic polymers, or a functionalgroup-containing long-chain polymer surface modification functional layer through the grafting reaction of the reaction gases with the functional groups on the surfaces of the hydrophilic polymers. The hyperfiltration membrane or nanofiltration membrane with the multi-layered composite structure has the advantages of high water flux, high cutting rate and stable chemical performances. The filtration membrane can be used for the production of domestic water, drinking water or water in special conditions, and is suitable for the medical field, food field, environmental protection field and the like.

The present invention relates to a composite membrane for gas separation and/or nanofiltration of a feed stream solution comprising a solvent and dissolved solutes and showing preferential rejection of the solutes. The composite membrane comprises a separating layer with intrinsic microporosity. The separating layer is suitably formed by interfacial polymerisation on a support membrane. Suitably, at least one of the monomers used in the interfacial polymerisation reaction should possess concavity, resulting in a network polymer with interconnected nanopores and a membrane with enhanced permeability. The support membrane may be optionally impregnated with a conditioning agent and may be optionally stable in organic solvents, particularly in polar aprotic solvents. The top layer of the composite membrane is optionally capped with functional groups to change the surface chemistry. The composite membrane may be cured in the oven to enhance rejection. Finally, the composite membrane may be treated with an activating solvent prior to nanofiltration.

The invention discloses a high-selectivity composite nanofiltration membrane and a preparation method thereof. The high-selectivity composite nanofiltration membrane comprises a nonwoven layer and a polymer porous supporting layer; and the porous supporting layer is provided with one or two polyamide surface layers prepared by reacting polyamine and/or amine polyalcohol with chlorine polyacyl. Compared with the prior art, by forming one or two polyamide surface layers on the porous supporting layer through an interfacial polymerization method, the nanofiltration membrane has increased thickness of a surface layer, has more smooth, hydrolysis-resistant, oxidation-resistant and scratch-resistant surface, and improves pollution resistance; and the surface of the membrane can carry negative or positive charges, so that the composite nanofiltration membrane has a high-selectively functional desalting layer; besides, the method for preparing the composite nanofiltration membrane is simple to operate, high water flux and desalination rate are ensured under low pressure, and the service life of the membrane component is prolonged.

The invention discloses an advanced treatment system and method for high-concentration percolate in a comprehensive garbage disposal plant, belonging to the field of industrial waste water treatment. The system is formed by connecting a regulating tank, a coagulative precipitation tank, an upflow anaerobic sludge bed reaction tank, a primary anoxic and aerobic membrane bioreactor, advanced oxidation treatment equipment, a secondary anoxic and aerobic membrane bioreactor, nanofiltration membrane treatment equipment, an ozone contact tank and an active carbon filtering tower in sequence. According to the system, garbage percolate can be treated comprehensively, different pollutants in garbage percolate are treated in a classified way by combining physical, chemical and biological treatment,advanced treatment of garbage percolate is realized, and classified treatment for removing pollutants such as organic matters, heavy metals, ammonia, nitrogen and the like is performed, so that treated effluent strictly reaches the requirement of water pollution discharge degree limit in the Household Garbage Landfill Pollution Control Standard, the system runs stably for a long time, and treatment cost is lower than that of a secondary disc pipe reverse osmosis membrane process.

The invention provides a processing method for reducing and recycling organic waste water. The method comprises steps: (1) pre-treating waste water to obtain pre-treated out-water; (2) treating the out-water obtained from the step (1) through solid-liquid separation; (3) nano-filtering the out-water obtained from step (2); (4) treating nano-filtered concentrated water obtained from the step (3) to obtain out-water subjected concentrated water nano-filtering, returning to the step (3) for mixing the out-water subjected to concentrated water nano-filtering with the out-water subjected to solid-liquid separation, and performing nano-filtering; (5) performing first reverse osmosis treatment on out-water obtained from the step (3) through nano-filtering; (6) performing second reverse osmosis treatment on concentrated water obtained from the step (5) through first reverse osmosis treatment; and (7) evaporating and crystallizing a concentrated liquid obtained from the step (6) through second reverse osmosis treatment in order to obtain crystallized salt and evaporated concentrated water. The invention further provides a processing system of the method. Through the method and system, waste water is truly reduced and recycled.

The invention discloses a crosslinking hyper branched polymer composite nanofiltration membrane as well as the preparation method thereof. The crosslinking hyper branched polymer composite nanofiltration membrane is prepared by taking an ultrafiltration membrane as a basement membrane and crosslinking hyper branched polymer as a selecting layer through hyper branched polymer and the interfacial polymerization of polybasic acid, polybasic acyl chloride, polybasic anhydride and polybasic amine; and the interfacial polymerization takes the mixed solution of water and ethanol as the water phase and n-hexane, n-heptane or n-octane as the organic phase. As the hyper branched polymer has the spheroidal structure, a plurality of nano-voids exist in the interior of the molecule, so as to enable the selecting layer of the crosslinking hyper branched polymer composite nanofiltration membrane to be looser, and leads the nanofiltration membrane to maintain high flux and retention rate under the lower operating pressure. The nanofiltration membrane can be used in the fields of medicament, foodstuff, environmental protection, etc. The composite nanofiltration membrane is applicable to the separation and the condensation of high valence ions, low valence ions, neutral particles, drugs, food additives, etc.

The invention discloses a preparation method of an aromatic polyamide film modified by a ZIF-8 type metal-organic framework material. A ZIF-8 filling polyamide composite film is prepared on an ultrafiltration bottom film by an interfacial polymerization method, wherein nano-grade ZIF-8 particles are added into an m-phenylenediamine aqueous solution and/or a trimesoyl hexane solution; a polyamide ultrathin skin layer, to which ZIF-8 is added, is formed through interfacial polymerization. The preparation method has the advantages that by the use of a ZIF-8 nano-grade aperture and a three-dimensional multi-hole structure, the selectivity or the permeability of the aromatic polyamide film is improved; the prepared ZIF-8 filling polyamide composite film can serve as a nanofiltration or reverse osmosis film for removing organic matters from the aqueous solution; when the adding ratio of an organic phase or water phase solution, to which ZIF-8 is added, is 0.05-0.15% (w/v), the performance of the film is the highest, and the permeation flux and the retention rate can be increased at the same time; furthermore, the nanofiltration or reverse osmosis performance of the two-phase adding film is higher than that of a single-phase adding film.

The invention discloses an extraction and preparation method for micromolecule fishskin collagen peptide, which comprises the following technical steps of: taking the fishskin of freshwater fish as raw material; removing non-collagenous protein; carrying out steps of degreasing, deodorizing, smashing and the like; under the acidic condition, carrying out heating hydrolysis processing to collagenous protein; controlling the degradation degree of the collagenous protein with an enzymolysis method; obtaining a target micromolecule collagen peptide with a membrane separation method; recycling protease, and then carrying out nanofiltration desalting; and after activated carbon binding resin is decolored and deodorized, carrying out spray drying to obtain the colorless and tasteless micromolecule fishskin collagen peptide. The extraction and preparation method disclosed by the invention has a simple technology, the protease is recycled by membrane separation, and therefore the cost is saved. The prepared micromolecule collagen peptide is colorless and tasteless and can be widely applied to industries relevant to the health of the human body, such as health care food, biomedicine, and cosmetics.

The invention relates to a method for carrying out desalination and zero-discharge processing of power plant desulphurization wastewater by adopting an electrodialysis technology. The method comprises the following steps: neutralizing, precipitating, coagulating and filtering the power plant desulphurization wastewater and removing CODs (Chemical Oxygen Demands), heavy metals, F-ions, gypsum, silicon dioxide, hydroxide of iron and aluminum and other insoluble particles in waste water; separating C1-ions and other monovalent ions in clear liquid from SO3<2->, SO4<2-> and other divalent ions through nanofiltration; desalinating and concentrating water produced by the nanofiltration by adopting a multistage countercurrent reverse electrodialysis method. The method has the advantages that the concentration of the Cl-ions in nanofiltration concentrated water and electrodialysis freshwater generated by the method is lower, and the nanofiltration concentrated water and the electrodialysis freshwater can be returned for flue gas desulfurization; the content of NaCl in a small amount of electrodialysis concentrated water produced reaches above 12 percent, the bivalent ions and other impurities are removed by nanofiltration, and the electrodialysis concentrated water is further evaporated and concentrated, so that chlorine-alkali industry electrolytes and NaCl salt can be obtained. Through the method, the zero-discharge treatment and the resource utilization of the desulfurization wastewater can be realized.

A method for producing lactic acid, comprising producing lactic acid from a sugar-containing fermentation liquid in a fermentor by means of lactic acid-forming bacteria to result in a lactate salt, typically ammonium, sodium or potassium lactate, and isolating lactic acid by subjecting the fermented fermentation liquid to a first ultrafiltration step to result in a substantially polymer-free permeate comprising at least one lactate salt, acidifying the permeate to a pH value of below about 3.9, performing at least one additional isolation step in which the acidified permeate is subjected to nanofiltration and/or reverse osmosis, and preferably subjecting the resulting product to electrodialysis using bipolar electrodialysis membranes. Fermentation is preferably performed using whey protein as a nutrient substrate and by adding at least one protein-hydrolysing enzyme directly to the fermentor during the fermentation process so that hydrolysis of protein to amino acids takes place simultaneously with the fermentation of sugar into organic acid.

Porous poly(aryl ether ketone) (PAEK) articles are prepared from PAEK/polyimide blends by selective chemical decomposition and subsequent removal of the polyimide phase. Porous PAEK articles exhibit highly interconnected pore structure and a narrow pore size distribution. The porous PAEK articles of the present invention can be utilized as a porous media for a broad range of applications, including membranes for fluid separations, such as microfiltration, ultrafiltration, nanofiltration, and as a sorption media.

The invention discloses a preparation method of a high-throughput cross-linked polyimide solvent-resistant agent nanofiltration membrane. The preparation method comprises the following steps: interface polymerization, polyamines modification, chemical cross-linking and solvent activation. According to the preparation method disclosed by the invention, the polyamines modification on the surface of an original ecological membrane is carried out after the interface polymerization is carried out, so that the separation performance and the solvent-resistant agent performance of the membrane are obviously improved. The polyamines have more free amino groups, so that the cross-linking degree of an interface separation layer is greatly enhanced, and the solvent-resistant agent performance of the membrane is effectively improved; polyamines modified reagents containing different additives are adopted, so that the separation performance of the membrane can be improved. The preparation process disclosed by the invention is simple, and has good application prospects in the fields of separation of organic solvent systems and treatment on water containing organic solvents.

A method and system using hybrid forward osmosis and nanofiltration is disclosed for treating produced water containing contaminant species. The system comprises a forward osmosis cell and a downstream nanofiltration cell. A draw solution fluid cycles between the forward osmosis cell and the nanofiltration cell. The draw solution contains polyvalent osmotic agents producing polyvalent ions in the draw solution. The passage of monovalent ions through the nanofiltration membrane is hindered due to the presence of conjugate polyvalent ions.

A zero discharge process for separating sludge and salt from desulfurization wastewater includes a pretreatment process, a membrane treatment process and an evaporative crystallization process; in the pretreatment process, the desulfurization wastewater enters a raw water tank, an aeration fan introduces compressed air into the raw water tank, and the wastewater is lifted to first-stage reaction and clarification by a raw water pump; in the membrane treatment process, the incoming wastewater is first filtered by ultrafiltration, then enters a pH adjustment tank, and is pumped into a nanofiltration membrane separation system and a reverse osmosis membrane separation system; in the evaporative crystallization process, the incoming wastewater is first subjected to two-stage preheating, then enters a degasser, and finally enters an evaporative concentration system and a crystallization system.

The invention discloses a method for preparing low-voltage high-flux charged nano-filtration membrane by dynamic self-assembly, which is characterized in that polymer ultra-filtration membrane is taken as a basic film; polycation electrolyte and polyanion electrolyte are alternatively and dynamically self-assembled on the surface of the basic film to gain a selective separation layer and to prepare the nano-filtration membrane of charged surface; wherein, the used ultra-filtration membrane molecular weight cutoff is less than 0.1 million; the ultra-filtration membrane material is surface-charged or modified-charged polymer. Nano-filtration membrane preparation by polyelectrolyte dynamic self-assembly has high efficiency, simple and convenient method and controllable assembly process and film structure; pure water solution is used in the whole preparation process, which is green and environmental protective; the applicable polyelectrolyte has a plurality of types; the separation films with different performances can be obtained by adjusting the types of the polyelectrolyte and the assembly conditions. Furthermore, the prepared nano-filtration membrane has low operation pressure, high removal rate on high valence inorganic salts and far greater flux than the current commercial nano-filtration membrane and the nano-filtration membrane preparation method has good application prospect.

The invention provides a treatment system and treatment method for biochemical effluent of industrial wastewater. The treatment system comprises a flocculation sedimentation unit, a filtration unit, an advanced oxidation unit, an ultrafiltration unit, a reverse osmosis unit, a nanofiltration unit, an electrodialysis unit and an evaporation unit which are sequentially connected; and the water production outlet of the ultrafiltration unit is connected with the water inlet tank of the reverse osmosis unit, and the concentrated-water outlet of the reverse osmosis unit is connected with the water inlet of the nanofiltration unit. According to the invention, the treatment system and the treatment method utilize the coupling and synergistic effects of a physical-chemical method and a membrane technology to overcome the limitation of using a single technology, and the advanced treatment and desalination reuse of the industrial wastewater are realized; and the treatment system and the treatmentmethod have the advantages of strong adaptability to raw water, a high recovery rate of fresh water, a high concentration multiple of concentrated water, low energy consumption of evaporation and crystallization and the like, greatly improve the reuse rate of the industrial wastewater, reduce the amount of wastewater discharging, can be applied to the deep treatment and desalination reuse of various effluent wastewater, and promote the promotion and application of the technology in related industries.